In an effort to develop ever-more effective equipment for hunting and other sports, the archery industry has developed a wide range of arrowhead styles that are intended and suited for specific uses. One such style of arrowhead is the broadhead, a bladed arrowhead featuring multiple sharp cutting blades that are designed to greatly increase the effective cutting area of the arrowhead. This increased cutting area results in larger, more effective entrance and exit wounds in game hit by the arrowhead, leading to quick and humane kills and better blood trails.
While broadheads provide an improved cutting capability in comparison with non-bladed arrowheads (known as field points or nib points), many broadhead designs suffer from inferior aerodynamic properties when compared to their non-bladed counterparts. Broadhead blades deployed during flight of an arrow can result in undesirable effects, causing that arrow to veer off course from the flight path coinciding with the longitudinal axis of the arrow shaft.
Previous broadhead designs have attempted to improve the aerodynamics of the bladed arrowheads by hiding a substantial portion of each of the cutting blades within the ferrule during flight of the arrow, in a design known as an “expandable broadhead.” Upon impacting a target, the blades are deployed, opening up and exposing the sharp cutting surfaces of the blades.
Examples of such previous expandable broadhead designs are described by U.S. Pat. No. 8,197,367, hereby incorporated by reference in its entirety, and are illustrated by the examples depicted in FIG. 1A, FIG. 1B, FIG. 1C, and FIG. 2. FIG. 1A, for example, depicts an existing expandable broadhead design 100 with two cutting blades 104a and 104b. These cutting blades are rear deploying blades held in place with a shock-absorbing retaining device 105 consisting of an O-ring and/or collar that is designed to break on impact. The rear deploying design of the blades 104a-b enhances the kinetic energy of the expandable broadhead 100 on impact, ensures that the blades 104a-b deploy reliably, and increases the probability of substantial penetration into the target. With regard to various exemplary embodiments of such collars, U.S. provisional patent application Ser. No. 61/584,430 (filed Jan. 9, 2012, entitled Broadhead Collars) and U.S. patent application Ser. No. 13/736,680 (filed Jan. 8, 2013, entitled Broadhead Collars), are both incorporated herein by reference in their entirety.
The design 100 illustrated by FIG. 1A also features a two-sided “cut on contact” tip 102, a sharpened double-edged piece of steel inserted into the nose of ferrule body 103. The cut on contact tip 102 is designed to slice neatly through the hide of a target game animal and requires a low amount of energy for penetration.
Previous designs for expandable broadheads have incorporated cut on contact tips similar to cut on contact tip 102 of broadhead 100. FIG. 1B depicts an example of an existing expandable broadhead design 106 that includes a ferrule body 107, a cut on contact tip 108, two rear deploying blades 110a and 110b, and collar 112 as disclosed in U.S. provisional patent application Ser. No. 61/584,430 and U.S. patent application Ser. No. 13/736,680.
FIG. 1C depicts an exploded view of an example of another existing expandable broadhead design 115. This design 115 features a cut on contact tip 117, two rear deploying blades 121a and 121b, and a collar 123. The cut on contact tip 117 is inserted into the ferrule body 120 and secured with a threaded fastener 116. The rear deploying blades 121a-b are hidden within one or more blade recesses 119 in the ferrule body 120, and secured to the ferrule body 120 by a threaded fastener 122. FIG. 2 depicts an example of yet another existing expandable broadhead design 200, which includes a cut on contact tip 203 and three rear deploying cutting blades 205a, 205b, and 205c. 
Exemplary views of existing cut on contact tips are illustrated by FIGS. 3A-3C and FIGS. 4A-4C. FIG. 3A depicts a side view of cut on contact tip 300, FIG. 3B depicts a front view of cut on contact tip 300, and FIG. 3C depicts a top view of cut on contact tip 300. Similarly, FIG. 4A depicts a side view of cut on contact tip 400, FIG. 4B depicts a front view of cut on contact tip 400, and FIG. 4C depicts a top view of cut on contact tip 400.
While the cut on contact tips utilized by previous expandable broadhead designs can easily penetrate the hide of a targeted game animal with a low expenditure of kinetic energy, a need remains for an expandable broadhead design that features a chisel tip. Durability is one advantage provided by a chisel-tipped expandable broadhead, as the leading edge of the broadhead is the location most likely to sustain impact damage. The dense, sculpted chisel tip reduces the broadhead's susceptibility to such impact damage, especially when striking hard structures such as bone.
In addition to the chisel tip's resistance to impact damage, its comparatively large, dense structure increases the amount of mass in the nose of the expandable broadhead. This increase in density moves the center of mass of the projectile upon which the broadhead is mounted further forward, improving the flight characteristics of that projectile. The aerodynamics of the projectile upon which a chisel tip broadhead is mounted can be further improved by incorporating a spiraling, helical design for the chisel tip. This helical design directs air flow around the ferrule body of the broadhead, leading to increased rotation of the broadhead projectile and reducing the effects of side winds in flight. The effects of the directed air flow created by the chisel tip stabilize the flight path of the projectile to improve its flight characteristics and lead to enhanced accuracy and precision of arrow shots.
Furthermore, a chisel tip mounted on an expandable broadhead can result in an increase in the effectiveness of the deployment of the rear deployed cutting blades. The deployment of the cutting blades works best when the leading blunt edges of the retracted blades strike the hide of the targeted game animal on impact. By offsetting the alignment of the chisel tip's cutting edges with the alignment of the rear deployed cutting blades, the chisel tip ensures that the blunt edges of the retracted blades strike the animal's hide, causing the retracted blades to effectively deploy and expose their sharp cutting edges.
As discussed above, there is a need for an expandable broadhead design featuring a chisel tip that provides increased resistance to damage, results in improved flight performance, and aids in the effectiveness of deploying the expandable broadhead's cutting blades. Embodiments of the present invention, as described below, solve the need in the art for such a device.